Bozzette S A, Hays R D, Berry S H, Kanouse D E
Department of Medicine, University of California San Diego School of Medicine.
Med Care. 1994 Jul;32(7):716-31. doi: 10.1097/00005650-199407000-00005.
Acceptance of health status as an outcome in clinical trials of new treatments for HIV disease has been hampered by the lack of valid and clinically relevant means of summarizing differences across multiple dimensions. We formed a summary Perceived Health Index from health status measures adapted from RAND Medical Outcomes Study scale and contained in the HIV-PARSE survey instrument, which had been administered to a large number of participants in clinical trials for advanced HIV disease. The psychometric properties of the included health status scales were assessed using multitrait scaling and test-retest stability. Weights for the index were derived from regressions of Current Health Perceptions on the domain-specific health status scales. The effect of participant characteristics on weights was tested. Finally, the reliability and known-clinical groups validity of the index was assessed. Data were obtained from 1,862 clinical trial participants who provided a total of 7,352 observations. The mean CD4 count was 131. The internal consistency reliability of the multi-item scales ranged from 0.86 to 0.90, and items demonstrated excellent discrimination across scales. The domain-specific scales explained 59% of the variation in the Current Health Perceptions scale (P < 0.00001). The resulting Perceived Health Index was equal to 0.20 Physical Functioning + 0.15 Pain + 0.41 Energy/Fatigue + 0.10 Emotional Well-being + 0.05 Social Functioning + 0.09 Role Functioning. The strong positive bivariate relationship between the Cognitive Function/Distress scale and the Current Health Perceptions scale was subsumed by the combination of the other domain-specific scales in multiple regressions, so it does not appear independently in the index. The proportional weights used in the index were insensitive to variations in demographics. The reliability of the index was conservatively estimated to be 0.94. Patients with index scores in the lowest quartile had a 2- to 11-fold higher probability than those in the highest quartile of reporting various specific clinical events, and the index correlated significantly more highly with the number of such events than did the current health perceptions scale. The modified MOS health status scales included in the HIV-PARSE are reliable and valid in patients with advanced HIV disease. The Perceived Health Index provides a reliable and valid means of summarizing self-reported current health, correlates strongly with clinical indicators, and should be useful as a outcome measure in patients enrolling into clinical trials of therapies for advanced HIV disease. Regression based weights are a useful means of summarizing multidimensional measures.
在针对HIV疾病新疗法的临床试验中，由于缺乏有效且具有临床相关性的方法来总结多个维度的差异，健康状况作为一种结果的接受度受到了阻碍。我们根据从兰德医疗结果研究量表改编而来并包含在HIV-PARSE调查工具中的健康状况测量指标，构建了一个综合的感知健康指数，该调查工具已应用于大量晚期HIV疾病临床试验的参与者。使用多特质量表法和重测稳定性评估所纳入健康状况量表的心理测量特性。指数的权重来自当前健康感知对特定领域健康状况量表的回归分析。测试了参与者特征对权重的影响。最后，评估了该指数的可靠性和已知临床组有效性。数据来自1862名临床试验参与者，共提供了7352条观察结果。平均CD4细胞计数为131。多项目量表的内部一致性信度范围为0.86至0.90，各项目在不同量表间表现出良好的区分度。特定领域量表解释了当前健康感知量表中59%的变异（P<0.00001）。由此得出的感知健康指数等于0.20身体功能+0.15疼痛+0.41精力/疲劳+0.10情绪健康+0.05社会功能+0.09角色功能。认知功能/痛苦量表与当前健康感知量表之间强烈的正双变量关系在多元回归中被其他特定领域量表的组合所包含，因此在指数中未独立出现。指数中使用的比例权重对人口统计学变量的变化不敏感。该指数的可靠性保守估计为0.94。指数得分处于最低四分位数的患者报告各种特定临床事件的概率比最高四分位数的患者高2至11倍，并且该指数与此类事件数量的相关性显著高于当前健康感知量表。HIV-PARSE中包含的改良MOS健康状况量表在晚期HIV疾病患者中是可靠且有效的。感知健康指数提供了一种可靠且有效的方法来总结自我报告的当前健康状况，与临床指标密切相关，并且在晚期HIV疾病治疗临床试验的参与者中作为一种结果测量指标应该是有用的。基于回归的权重是总结多维测量的一种有用方法。
